Fumigant composition and process



Patented Sept. 8, 1953 COMPOSITION AND PROCESS.

Kenneth S. Iiarsten,- Westport, Conn, assignor' to R. T. Vanderbilt Company, Inc., New York, N. Y., a. corporation of New York No Drawing. Application April 13, 1951, Serial No. 220,965,

i Claims. 1

My invention. relates to. new pesticides. which are active in the vapor phase,- andalso. on contact- My invention also relates. to methods for the. application of such. pesticides...

A number of vapor phase pesticides, such as formaldehyde, methyl bromidabromine, ethylene dichloride, para dichlorobenzena. nitrogen trichloride, diphenyl and chloropicrin, have. been used.v for various. preservative: purposes, and. are useful and: of value in. controlling certain molds, bacteria. and. insect. pests. certain disadvantages, suchas specifiicity, susceptibility to decomposition or too ready Vela-- tility for sustained effect.

I havefound that. compoundstalling within the scope of the, formula it cools Y coolnwherein X is bromine or chlorine, wherein Y is hydrogen, bromine or chlorine and Rb and R2 are alkyl radicals having from. L to- 4 carbon atoms, or mixtures of: such compounds, provide They have; however, l

2. Example II One gram of diethyl bromomalonate was impregnated on 5 grams of'cotton batting, and the impregnated batting was placed in a closed container' of 50,000 ml. inside volume. The container was kept closed for thirty-six hours. Open Petri dishes containing agar-culture medium freshly inoculated with a mold ('Aspergillus niger) and withbacteria (Micrococcus aureus) were then placed in the container. The Petri dishes were thereafter removed at intervals of time and it was found that thebacteria were killed by exposure to the vapors of the chemical for forty-eight hours. The mold was inhibited, but was not killed. Only a small part of the compound, ap-

' proximately 0.01 gram, vaporized during the forty-eight hour period.

Example III In this example, the procedure of Example II i wasrepeated, 1 gram of diethyl dibromomalonate a new and effective means iorcontrolling fungi,

These chemicals provide a and efiectrve means for; sterilizing surfaces, simply by placing the materials. to. be: sterilized in an enclosed vessel in which a small amount of the. chemical? is allowed to vaporize. Moreover, these chemicals havd a pleasant odor and be used in a. num ber of ways in. which: pesticides have been here.- tofore usedinthe art, for example, as. aerosols, inimpregnated paper, in impregnated powders; in water emulsions, in solution in oils, and so forth, to provide an environment in which the chemicals are present... chemicals are also useful as preservatives for. pasta. paint, cnttin-a oils, textiles, and so forth.

The following examples illustrate the diversity of ways in which these compounds are useful.

Example I- Wheat was treated with 0.1% by weight; of diethyl bromomalonate hytumbling, and was thereafter placed, in a closed container.. Adult. confused flour beetle insects placed; in the container with the treated seeds died in less than twenty-four hours; Insects placed in. a similar container with untreated wheat remained alivei beingused in place. of the diethyl bromomalonate used in. Example II. It" was found that the mold and; the bacteria were killed by the vapors of the chemical in; twenty-four hours.

Example IV A bundle of dry broom corn was placed in a 13 gallon wax-lined fiber drum. An open pan of water was placed in the drum with the broom corn to; maintain a relative humidity of quantity of diethyl bromomalona-te was then placed on a small wad of cotton in the bottom of the drum. at. some distance from the broom corn, and the drum was-thenlrept closed except during examination. 0.1. ml. of diethyl bromomalonate prevented mold growth on the broom. corn for three weeks, and 1 m1. prevented mold growth for more than 6 weeks. Broom corn set up under comparable conditions, but with the diethyl bromomalonate absent. was. covered with. a heavy mold. growth in one-week:

Example: V

The procedure of Example IV was repeated, but using diethyl dibromomalonate in place of diethyl bromomalonate. 011 ml. of the diethyl dibromomalonate prevented. mold growth for. four weeks, and. 1. ml. therecufv prevented. mold. growth for more than six weeks.

Example V'I' Diethyl bromomalonate in the amount of 2%, by weight was incorporated into; awater-emulsiv fiable machine tool cutting. oil. 7 The, concentrate was then diluted with 20 volumes of water. 5% by weight of iron chips were added to the water emulsion, and the emulsion was then inoculated with 1 cc. of spoiled oil per 200 ml. of water emulsion. Bacterial plate counts were made at the start of the test, and after '7, 14, 21, 28 and 35 days. After 35 days the bacterial count on untreated oil emulsion, which was used as a blank, was 38 million bacteria per ml, the count on the emulsion containing 2% diethyl bromomalonate being half a million. count after inoculation was 200,000 bacteria per ml.

Example VII The procedure of Example VI was repeated, using diethyl dibromomalonate in place of the diethyl bromcmalonate. After 35 days, the bacterial count of the emulsion was 10,000 bacteria per ml.

Example VIII A 0.4% by weight solution in water of ordinary hard soap was prepared. To this solution was added 2% by weight, based upon the weight of the soap, of diethyl bromomalonate. To 200 ml. of the soap and toxicant solution was added 1 ml. of a twenty-four hour nutrient broth culture of M. aureus. The soap solution was allowed to stand for fifteen minutes, and then a bacterial plate count was made on the solution. The count on the untreated control soap solution was 200,000 bacteria per ml., whereas that on the sample which had been treated with diethyl bromomalonate was 70,000 bacteria per ml.

using diethyl dibromomalonate in place of diethyl bromomalonate. The solution containing The original bacterial 4 Example XIII The procedure of Example XII was repeated, using diethyl dibromomalonate in place of the diethyl bromomalonate. In this case, spoilage of the soya flour solution was prevented for more than forty-six days.

Various modifications may be made in the procedures of the specific examples to provide other embodiments which fall within the broad scope of my invention. Thus, as has been stated above, the toxicants defined by the generic formula given above can be applied in the same manner in which volatile, liquid toxicants have heretofore been used. For example, aerosols may be prepared'composed of about 2 parts by weight of the toxicant, such as diethyl dibromomalonate, and

about 98 parts by weight of a suitable propellant, such as Freon 12 or methyl chloride.

Furthermore, impregnated powders may be prepared by suitably admixing from about 5 to about parts by weight of diethyl dibromomalonate or one of the other toxicants mentioned above with from about 95 to about 50 parts by weight of a suitable solid carrier, such as prophyllite, chalk, pyrethrum mare, diatomaceous earth, walnut shell flour, and so forth. As is well understood in the art, the particular amounts of toxicant and solid carrier chosen will depend upon various factors, such as the ability of the solid carrier to absorb the toxicant and upon the particular strength desired for the final composition.

Where it is desired to employ the toxicant emulsified in water, a mixture of, for example, 95 parts by weight of diethyl dibromomalonate or other compounds falling within the scope of the generic formula given above may be mixed with 5 parts by weight of Triton X-100 to form an emulsion concentrate, which can be dispersed in the diethyl dibromomalonate had a count of,

27,000 bacteria per ml. upon standing for the 15 minute period.

Example X Example XI The procedure of Example X was repeated, using diethyl dibromomalonate in place of diethyl bromomalonate. In this case too, the casein solution containing the toxicant was unspoiled after sixty days.

Example XII Diethyi bromomalonate was incorporated into a 5% solution of soya flour, a commercially used adhesive solution, in a concentration of 0.5%, based on the weight of the dry adhesive. The solution used as a blank and containing no toxicant putrefied in six days, whereas the solution containing the diethyl bromomalonate was pro tected for forty-six days.

- water using 2 pounds of concentrate per 100 gallons of water. Also, if desired, an emulsion concentrate which may similarly be dispersed in water mat be prepared using, for example, 50 parts by weight of diethyl dibromomalonate, 40 parts by weight of isopropyl alcohol and 10 parts by weight of monoethanol ammonium oleate.

Where it is desired to use the toxicant in solution, suitable solutions can be prepared using xylene, alkyl naphthalenes or kerosene as the solvent. The compositions of my invention find application in the preservation of fruits, such as apples, peaches, oranges and bananas, which are being transported or stored. They are also highly useful in the preservation of freshly harvested farm crops, such ashay, grain, seed, corn, and so forth, which are undergoing curing. A wide variety of applications for my compositions will suggest themselves to those who are skilled in this field.

I claim:

1. A pesticidal composition of matter comprising as an active ingredient at least one compound of the formula 3. A method for the preservation of materials subject to pesticidal attack which comprises contacting such materials with at least one compound of the formula X COOR! Y COORa 4. A method as in claim 3 in which X and Y 15 are bromine and in which R1 and R2 are ethyl.

KENNETH S. KARSTEN.

References Cited in the file of this patent FOREIGN PATENTS Country Date Germany June 30, 1930 Number OTHER REFERENCES 10 Pennsylvania (1919) at page 491.

A Second Index of Patented Mothprocfing Materials by R. C. Roark. U. S. Department of Agriculture, Bureau of Chemistry and Soils, Insecticide Division, February 1933 at page 32.

J. Agri. Research, volume 12, pages 579 to 587 (1918).

Chemical Abstracts, volume 16, page 2848 

1. A PESTICIDAL COMPOSITION OF A MATTER COMPRISING AS AN ACTIVE INGREDIENT AT LEAST ONE COMPOUND OF THE FORMULA 